Policy and Charging control (PCC) is a policy and charging control mechanism defined by the 3rd Generation Partnership Project (3GPP). An architecture of PCC is shown in FIG. 1.
A core of the PCC mechanism is: When establishing a data flows bearer, a Gateway device requests a data flow control and charging policy from a Policy and Charging Rules Function (PCRF) entity; according to subscriber information stored in a Subscription Profile Repository (SPR), information about a bearer layer provided by the Gateway, and some local policies configured in the PCRF by an operator, the PCRF generates a dynamic charging and control policy about a service data flow or determines a to-be-activated static charging and control policy about a service data flow, and delivers a command to the Gateway to install the generated dynamic policy or activate the determined static policy that is stored in a Policy and Charging Enforcement Function (PCEF); and the Gateway performs resource allocation, data flow control, and charging control according to the installed/activated policy. The mechanism can implement precise control over a service data flow according to an operator policy, so as to implement refined operation on bandwidth.
Related concepts are defined as follows:
The PCEF entity is located in the Gateway and is configured to execute a dynamic or static control policy. The Gateway includes an endpoint established on a bearer, such as a Gateway GPRS support node (GGSN) or a PDN Gateway (P-GW).
The PCRF entity is responsible for generation of policies of Quality of Service (QoS), bandwidth, gating control, charging, or the like when user equipment uses a service in a home network.
The SPR stores user subscription data and maps to an entity in an existing system, where the entity may be a home location register (HLR), a Home Subscriber Server, (HSS), an Online Charging System (OCS), or the like.
A Traffic Detection Function (TDF) unit is configured to detect an application. Detection herein does not refer to parsing using a 5-tuple at a network layer, but refers to deep packet parsing.
The OCS receives a charging event and user use information that are reported by the PCEF after the PCEF is triggered.
A rating group (also referred to as Rating Group) is used to aggregate one or more services having same costs (also referred to as cost) or a same rating (also referred to as Rating) type, and is used for charging system rating.
In a long term evolution (LTE) network, a user mobile phone is always connected to a network (also referred to as Always-on). To implement Always-on, when being attached, the mobile phone establishes a default bearer (also referred to as Default Bearer), where the bearer exists at an entire stage in which the user is connected to the network.
When a mobile phone is in an Always-on mode, no matter whether a user uses a service, at least one Internet Protocol (IP)-Connectivity Access Network (CAN) Session exists. One IP-CAN Session involves session establishment on multiple interfaces such as Gy and Sd, and the session is maintained in entire IP-CAN Session duration, which causes a waste of resources of an OCS, a PCEF, or the like.